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木质残体是油松针阔混交林的重要组成部分,具有多种的生态功能,对生态系统的稳定和发展有着不可忽视的作用。以陕西省黄龙山林区为研究区域,设置1 hm2(100 m×100 m)的固定样地,研究典型油松针阔混交林木质残体的储量组成、优势树种的空间关系、腐烂特征及密度与含水量,研究结果表明:(1)研究区油松针阔混交林内木质残体的总储量为10.73 t·hm–2,倒木是林分内木质残体的主要来源。在径级组成结构上,径级20 cm以上的木质残体储量占总储量的绝大部分。腐烂等级中,以腐烂等级Ⅱ与腐烂等级Ⅲ的木质残体贮量最多;(2)利用线性模型模拟该林分木质残体的分解密度与含水量,其拟合结果显示木质残体的密度随着腐烂等级的增加而呈现下降趋势,而含水量则随着腐烂等级的增加而呈现升高的趋势;(3)林分内主要研究树种(油松、白桦和山杨)之间在小空间尺度上呈负关联,大尺度下呈正关联,顶级树种与先锋树种间达到互利共生,群落具有较大稳定性。林分内种间竞争的结果将为地带性顶级树种油松代替白桦与山杨等先锋树种。天然油松针阔混交林木质残体的贮量组成及腐烂特征反映了该区森林群落演替后期阶段木质残体的结构特征,本文的研究结果为我国黄土高原针阔混交林生态系统的管理和保护以及可持续经营提供科学依据。
Woody debris is an important part of Pinus tabulaeformis mixed forest, with a variety of ecological functions, the stability and development of the ecosystem has a can not be ignored role. Taking the Huanglongshan forest area of Shaanxi Province as the research area, the fixed sample of 1 hm2 (100 m × 100 m) was set up to study the reserves composition, the spatial relationship, the decay characteristics and the density of dominant species in the coniferous and broadleaf mixed forest The results showed that: (1) The total reserves of woody debris in Pinus tabulaeformis mixed forest was 10.73 t · hm-2 in the study area, and the inverted wood was the main source of woody debris in the forest. In the structure of the diameter class structure, the diameter of more than 20 cm wood residue reserves accounted for the vast majority of the total reserves. (2) The linear density model was used to simulate the decomposition density and water content of woody debris, and the fitting results showed that the density of woody debris With the decay level increasing, the declining trend appears, while the water content shows a rising trend with the increase of decay level. (3) The main research species (Pinus tabulaeformis, Betula platyphylla and Poplar) Spatial scales were negatively correlated, large-scale was positively correlated, the top species and pioneer species to achieve mutualism and symbiosis, the community has greater stability. The result of the interspecific competition within the stands will be the replacement of pioneer tree species such as birch and aspen for the top genus Pinus tabulaeformis. The composition and decay characteristics of woody debris in the natural Pinus massoniana and Pinus elliottii mixed forest reflect the structural characteristics of woody debris in the later stage of forest community succession. The results of this paper are the management of the ecological system of the coniferous and broad-leaved mixed forest in the Loess Plateau, Protection and sustainable management to provide a scientific basis.